1. Field of the Invention
The present invention relates generally to electrically conductive bracelets and more specifically to an electrically conductive bracelet having an electrically conductive inner surface and an electrically insulated outer surface.
2. Description of the Related Art
The routine handling of static-sensitive electronic components is plagued by problems related to static electricity. A discharge of static electricity may damage sensitive electronics, particularly integrated circuits and other microelectronic components. An over-voltage of the static electricity may disable or destroy such electrical components. Such damage may be caused by a small electrical discharge. For instance, certain junctions within the components may be destroyed by as little as a 50-volt potential.
An individual may easily generate large amounts of static electricity while performing simple day-to-day activities. For instance, a person walking on a carpet on a dry day may accumulate as much as 30,000 volts of potential. An individual may additionally generate thousands of volts of potential by simply changing his position in his chair or handling a polystyrene foam cup.
A person who has generated static electricity may inadvertently discharge the static electricity into an electrical component through accidental contact or touching. Accordingly, it is common practice for personnel in industries in which electrical components are frequently handled or assembled to take measures to limit the discharge of static electricity into the components. Such a discharge may be prevented by keeping the worker at a zero electrical potential.
A grounding band is a tool that may be helpful in keeping the worker at or near a zero electrical potential. A typical grounding band includes a conductive surface that is electrically connectable to the wearer. Many grounding bands achieve such an electrical connection by placing the conductive surface in contact with the wearer's skin. The conductive surface is typically electrically connected to a grounding cord which leads from the band to a grounded electrical connection. Therefore, the electric charge is dissipated from the user to ground.
Many grounding bands are commonly constructed from a fabric material. An electrically conductive thread is typically included within an inner surface of the grounding band and may be brought into electrical communication with the wearer. The fabric grounding band may additionally include a fabric outer surface which may insulate the wearer from electrical shock in the event that the band came in contact with a live or ungrounded electrical instrument, which are commonly found in the production place of the electrical industry.
Although a fabric grounding band may initially serve as a sufficient tool for keeping a worker at or near a zero electrical potential, repeated use may reduce the effectiveness of the band. More specifically, dirt and sweat may insulate the electrically conductive thread from the user's skin. Therefore, electrical communication between the user and the electrically conductive band tends to be disrupted by the dirt and sweat.
Furthermore, certain electronics require handling in a controlled environment referred to herein as a clean room. Certain precautions are taken in order to reduce the number of airborne particles within the clean room. For instance, air flow, temperature, pressure, and humidity may be carefully controlled in order to maintain the standards of the clean room. Airborne particles may be introduced into the clean room by people and equipment contained therein. As such, additional measures may be taken in order to limit airborne particles introduced via people and equipment.
Fabric grounding bands discussed above tend to introduce contaminating particles into such an ultra clean environment. For instance, the fabric may rip and fray, thereby creating airborne particles which may be potentially hazardous in a clean room environment. In addition, the fabric may easily become contaminated or stained, which may also create problems within the clean room, such as quality control issues and high rejection rates.
Therefore, most grounding bands used in clean rooms are constructed from metal. Most metal bands that are used in a clean room are constructed from stainless steel to mitigate the development of stains on the band. Metal is a highly conductive material, which makes it a suitable material for use in the grounding band. However, if the metal is exposed, a dangerous conductive path may be created which may create a dangerous electrical shock if it comes in contact with a live or ungrounded electrical instrument, which is commonly found in the production place in the electronic industry.
Some metal bands include a layer of paint disposed on the outer surface to insulate the band and mitigate electrical shock of the wearer. However, stainless steel tends to be difficult to paint due to the presence of an oxide layer. In addition, any sharp corners located on the band make it difficult to paint.
Therefore, as is apparent from the foregoing, there exists a need in the art for an improved electrically conductive band which facilitates electrical protection from an electrical shock.